Hi Molly;
Stellarium is great for free software. It would be pretty darn good for paid software too, but it's great that it is free.
There are some commercial programs that beat Stellarium, including StarryNight, but for answering the casual "what is that bright star?" question, it is hard to knock Stellarium.
As far as getting hit, it depends on how you define it. The earth is a pretty big place, and we plow through a lot of dust in our orbit around the sun. In fact, the estimate is that we gain about 100 tons of mass every day from all the dust and small meteors that we hit (or that hit us, depending on how you look at it).
Currently the odds of getting hit by a particular asteroid in 2036 are 1:250,000. I say 'currently' because we don't have a good enough fix on its orbit to say for sure, but the chances are that after the next couple of passes that our chances of being hit by it are going to drop to zero. We discuss this on the asteroids page.